[PATCH v8 11/22] ASoC: tegra: Add fallback implementation for audio mclk

[Sowjanya Komatineni]

mclk is from clk_out_1 which is part of Tegra PMC block and pmc clocks
are moved to Tegra PMC driver with pmc as clock provider and using pmc
clock ids.

New device tree uses clk_out_1 from pmc clock provider as audio mclk.

So, this patch adds implementation for mclk fallback to extern1 when
retrieving mclk returns -ENOENT to be backward compatible of new device
tree with older kernels.

Fixes: 110147c8c513 ("ASoC: tegra: always use clk_get() in utility code")

Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Reviewed-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
---
 sound/soc/tegra/tegra_asoc_utils.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/sound/soc/tegra/tegra_asoc_utils.c b/sound/soc/tegra/tegra_asoc_utils.c
index 536a578e9512..74d3ffe7e603 100644
--- a/sound/soc/tegra/tegra_asoc_utils.c
+++ b/sound/soc/tegra/tegra_asoc_utils.c
@@ -191,9 +191,21 @@ int tegra_asoc_utils_init(struct tegra_asoc_utils_data *data,
 
 	data->clk_cdev1 = clk_get(dev, "mclk");
 	if (IS_ERR(data->clk_cdev1)) {
-		dev_err(data->dev, "Can't retrieve clk cdev1\n");
-		ret = PTR_ERR(data->clk_cdev1);
-		goto err_put_pll_a_out0;
+		if (PTR_ERR(data->clk_cdev1) != -ENOENT) {
+			dev_err(data->dev, "Can't retrieve clk cdev1\n");
+			ret = PTR_ERR(data->clk_cdev1);
+			goto err_put_pll_a_out0;
+		}
+
+		/* Fall back to extern1 */
+		data->clk_cdev1 = clk_get(dev, "extern1");
+		if (IS_ERR(data->clk_cdev1)) {
+			dev_err(data->dev, "Can't retrieve clk extern1\n");
+			ret = PTR_ERR(data->clk_cdev1);
+			goto err_put_pll_a_out0;
+		}
+
+		dev_info(data->dev, "Falling back to extern1\n");
 	}
 
 	ret = tegra_asoc_utils_set_rate(data, 44100, 256 * 44100);
-- 
2.7.4